Here’s something useful: a full listing of every track featured in David Cantwell’s and Bill Friskics-Warren’s Heartaches by the Number: Country Music’s 500 Greatest Singles — with easily playable (full) previews of all of them. Nice! I purchased this book several months back, and while I haven’t fully (yet) gotten into the writing itself, I did make a few great discoveries through it, among them the Conway Twitty/Loretta Lynn duet at #16, and Connie Smith’s searing “Burning a Hole in My Mind” at #46. (Also lots of stuff on the same site about Marsh’s singles tome.)
RockCritics.com 
I feel a Spotify playlist coming …
We don’t have Spotify in Canada, I’m not even sure how it works, but definitely, there’s a good playlist in there. My knowledge of and taste in country is kind of bizarre and very hit and miss (“bizarre” in the sense that there’s absolutely no coherency or consistency to it), and I’ve listened to a number of things in their Top 500 I didn’t care for at all, but I’ve also latched on to at least a handful of songs (thus far) that are really amazing.